Fire extinguisher



Nov. 28, 1939. c. H. LINDSAY 2,181,488

FIRE EXTINGUISHER Filed April 9, 1937` BY Q n @i MW/@mok s. 2'?

Patented Nov. 2s, 1939 mm @FFI 2,181,4ss FIREEXTINGUISHER Charles H. Lindsay, Elmira, N. Y., assignorto American-LaFrance-Foamite Corporation, Elmira, N. Y., a. corporationof New York Application April 9, 1937, Serial No. 135,837-

6 Claims.

The invention relates to fire extinguishers in which a liquid, usually one of low freezing point, is expelled from a container by'gas pressure released therein at the time of discharge, such gas being normally stored within the container in a capsule -or flask. The invention relatesv more directly to such extinguishers, in which the act vof inversion of the container operates to jcause the puncturing ofthe sealing disc of the gas flask, thus to release the pressure, and the object, among other things, is to improve on this class 0f extinguisher and particularly to compensate for pressure variations incident to extremes of temperature, i

In the accompanying drawing,

Fig. 1 represents an extinguisher of the type referred to in inverted position and partly broken out to show the interior.

v Fig. 2 is a section of the 'flask and its mounting. Figs. Sand 4 are respectively sections on lines III-III and IV-IV of Figs. 5 and .6, and

Figs. 5 and 6 are details of the puncturing mechanism in the form at present preferred.

The container marked I is provided with an outlet hose"2 and a screw closure cap 3, by which it can be set on its head when inverted and in action. The cap has a central anvil 4 against which it can be bumped on the floor or ground, to produce or insure operation. The container I may be assumed to contain an appropriate quantity of any liquid, a solution of calcium chloride, for example.

The gas flask 5 contains liquid carbon dioxide, normally confined therein by a rupturable disc 6, which is clamped to and within the tubular head l of the flask by means of a tubular clamp plu'g 8. 'I'he bore through the plug and flask head i`s continued to near the opposite end of the flask (upper in the drawing) by means of a dip tube 9, the function of which will be presently explained.

Thus organized, the flask is screwed or otherwise attached to a carriage ID mounted on a fixed post I I which may be an integral part of the screw cap, as shown, although the form of carriage mounting is subject to variation, according to preference. 'I'he carriage and hence the flask, are adapted to slide back and forth on the post II being confined thereon by a washer I2.

The sealing disc E is intended to be-punctured by the punch or piercer I3, which is threaded or `otherwise fastened to the guide post II. The

blade portion of the punch is formed of twoy diameters, the free end or head I4 being larger than its shank part I5 and also desirably bevelled or sharpened, or otherwise shaped, to make an easy out of the disc, folding as it passes the disc. y

In the erect position of the extinguisher the flask and its carriage hang from the washer I2 and thehead I4 of the punch thenoccupies the i5 bore in the clamp plug 8 in about the relation indicated in Fig. 2 which shows the parts 'at the instant of inversion and beforefthe flask has started to move. When the extinguisher is inback the cut flap,

verted and bumped on the iloorthe impact causes I] 0 the flask to slide on its post relatively to'the punch and the latter punctures the disc, the parts then assuming the relative position shown in Fig.

5. 'Ihe disc being thus opened, the confined gas rushes out of the flask around the punch and M through the carriage ports I6 into the container where its action on the liquid expels it through the hose. If the pressureof the gas in the flask is high, as it will be when the temperature is normal, say 70 F. or above, the reaction of the 20 escaping gas will causethe flask to recoil or blow back upwards to its original position limited by the Washer I2, in which case the head I4` of the punch will occupy the part I1 of the bore in the clamp plug 8. If, however, cthe flask pressure v25 is low, due to abnormal low temperature, lsay zero or below, or other cause, the gas reaction or recoil will not be su'cient to lift the weight Aof the flask and it will therefore remain in the position to which it fell, in which the head I4 occu- 30 pies the part I8 of the discharge bore, this being the part that is within the flask head 1.

The bore I 'l is smaller than the bore I8, `and therefore in the case of high flask pressure (recoiled flask) the escape path for the gas is rela- 35 tively restricted, whereas in the case of lower pressure it is relatively larger. 'Ihe dimensions of the bore and the punch head diameters are mutually calibrated with reference to the size or weight of the flask and its associated parts so 40 as to take care of the two extremes of temperature, as just described. The result of this automatic control is that an adequate pressure, suillcient to expel the extinguisher liquid with a proper stream range is instantly established even k4,5 when the carbon dioxide in the flask is very cold, and yet is not excessive at higher or normal temperature say 70 F. or above anda practically constant pressure is maintained in the container throughout the discharge period.

The dip tube 9 contributes to the proper action. In the inverted or operating position it reaches up above the level of the liquid carbon dioxide and therefore delivers gas only into the discharge bore. The gas so delivered, it will be understood is derived from the vaporizing liquid which, at a given temperature, will vaporize only as fast as the previously vaporized gas can escape through the narrow bore, in consequence of which the pressure admitted to the container will be properly controlled by the calibration; except for this fact liquefied carbon dioxide would flow directly through the calibrated passages with an excessive gas development and an irregular and undesirable action. The dip tube also minimizes the possibility of rust or scale in the flask falling into and clogging the calibrated outlet and avoids the use or need of screens for this purpose.

It may be noted that the functioning of the extinguisher in the manner described is essentially the result of the relative movement `or the flask and piercer, no matter how brought about, and the mutual calibration of the piercer and the discharge bore whereby the effect of gas reaction is to place the parts in the how-restricting position whereas if there is no gas reaction, the parts remain in the position to which they were brought by the force of puncturing the disc. It will be obvious that the calibrated discharge bore may be formed in the flask head structure or otherwise as preferred.

l. In an extinguisher, the combination of a container for liquid to be expelled, a disc-sealed flask of liquid carbon dioxide movable therein between two limits of position and having a discharge bore of predetermined dimension, a relatively xed piercer adapted to operate in said bore and against which the flask may fall to puncture its sealing disc, said piercer and bore being mutually calibrated to provide a smaller gas escape path when the bore is in its position farthest removed from said piercer than when nearest thereto.

2. In an extinguisher, the combination of a container for liquid to be expelled, av disc-sealed flask of liquid carbon dioxide having a discharge bore of predetermined dimension, a piercer adapted to occupy said bore, said flask being relatively movable with respect to said piercer in one direction by a force adapted to puncture said disc and in the other by the reaction of the escaping gas, said bore and piercer being mutually calibrated to provide a smaller gas escape path in the relative position of said parts produced by gas reaction than in the position produced by said other force.

3. In an extinguisher, the combination of a container for liquid to be expelled, a disc-sealed flask of liquid carbondioxide having a discharge bore of predetermined dimension, a piercer in said bore adapted to puncture the disc, said ask being relatively movable With respect to said piercer in one direction by a force adapted to puncture the disc, and in the other direction, by the reaction of the escaping gas, said ask having a discharge outlet arranged to discharge gas only through said bore and said bore and piercer being mutually calibrated `toprovide a smaller gas-escape path through the bore on thergasreaction position of said parts.

4. In lire extinguishing apparatus, the combination with a movably mounted flask containing liquid carbon dioxide having a discharge outlet and means operated by flask recoil for governing the size of said outlet, said means providing maximum discharge cross area at minimum temperature.

5. In fire extinguishing apparatus, the combination with a disc-sealed flask containing liquid carbon dioxide, the disc being clamped over an outlet bore in the flask head by a disc clamp which has a continuation bore of smaller cross area, of a piercer having an enlargement adapted to occupy either bore.

6. In an extinguisher, the combination of a iiask of liquid carbon dioxide having a gas outlet member, a member adapted to occupy said outlet member, saidy second-named member being relatively movable with respect to said outlet member and mutually calibrated therewith to provide a greater degree of restriction to gas flow through said outlet member in one relative position of said members than in another, one of said members being normally subject to a constant force tending to establish the least degree of restriction and also to the opposing kinetic force of the discharging gas tending to move it to its position establishing the greater degree of restriction, and releasable means for normally confining the gas under pressure in said flask.

CHARLES H. LINDSAY. 

